The conventional type of a micro stepping motor such as shown in FIG. 1 comprises a rotor 1, a magnetic core 2 having a coil winding L, a stator constructed of two stator pieces 3A and 3B which are fixed to the magnetic core 2 and are opposed with respect to each other around the rotor. The eccentric pins 4A and 4B are respectively positioned in long holes provided in stator pieces 3A and 3B. It is necessary to accurately adjust the position of said stator pieces 3A and 3B by means of said eccentric pins 4A and 4B for driving the motor in the best condition.
Further, it is difficult to mass-produce and finish the circular portion 3a and 3b of said stator pieces 3A and 3B with a high degree of accuracy. Moreover, the stationary position of said rotor is decided by the fixing phase said stator pieces 3A and 3B after variably adjusting them to obtain the best motor operating condition.